Roof support cap for mining prop means



March 1, 1966 G. DOMMANN ETAL 3,237,903

RGOF SUPPORT CAP FOR MINING PR01 MEANS Filed June 25, 1964 @1L s Il A JQDLLII United States Patent O ROOF SUPPORT CAP FR MINlNG PRGP MEANS Gnther Dommann, Wethmar, near Lumen, Erich Hottmann, Altlunen, and Hermann Har/ers, Werne an der Lippe, Germany, assignors to Gewerkschaft Eisenhutte Westfalia, Wethmar, near Linien, Germany Filed .lime 23, 1964, Ser. No. 377,419 9 Claims. (Cl. 24S- 357) The present invention relates to a roof support cap for mining prop means, and more particularly to such a cap having a pair of bearing parts displaceable with respect to each other from a position in abutment with each other, whereby to form a bearing recess for a prop head of a mining prop, to a position removed from the abutment position, 'whereby to permit clearance between said bearing parts, and in turn, disengagement of the cap from a prop head at such bearing recess for removal of the cap.

Mining prop means are used, for example, in long wall mining operations in which the mining prop means serve to support the mine roof from cave in. Often, the mining prop means are used in the form of a mining frame, including a pair of extensible pit props or mining props mounted in tandem on a longitudinal plate or skid and having a roof support cap situated on the upper end portions of the props, whereby to form a more or less rectangular frame. The portions of the roof cap situated on the individual props may be connected integrally with one another or may be hingedly connected to one another such that each prop supports a corresponding roof cap thereon. In order to position safely the particular roof cap on the prop therebelow, a bearing recess in the form of a socket is usually provided, so as to permit a certain amount of play between the prop and cap yet prevent unintentional disengagement therebetween or loss of the bearing support at the recess between the head of the prop and the cap thereabove.

Usually, the pit props or mining props are hydraulically or pneumatically operated and resemble hydraulic or pneumatic jacks, composed of upper and lower telescoping members operating in the manner of a piston cylinder arrangement. Nevertheless, a maximum limit of extension and a minimum limit of retraction of the telescoping members with respect to one another is obviously inherent in the arrangement depending upon the linear dimensions of the prop members.

ln mining operations conducted along mineways, especially with regard to the mining of low seams of mineral, such as coal seams of reduced vertical dimensions, sometimes it happens that the mine roof is situated with respect to the prop frame on the mine oor, such that even in the maximum position of retraction of the props of the frame, there is no clearance between the roof support cap, and the prop on which the same is situated for the removal of the root cap from the upper portion of the prop, as for example, where the prop frame is to be dismantled and repositioned at another place. As a result, a significant expenditure of time and eiort has to be devoted to the releasing of the caps from the heads of the props against which the bearing recesses of the caps are jammed due to the low mine roof and either the undesirability or impossibility of further reducing the height of the props.

Accordingly, any construction which may be provided to make possible the removal of the caps from the props under the aforesaid conditions would find wide application in mining operations, especially lwith regard to low or thin horizontal seams. An arrangement would have to be provided in which the removal of the caps from the props could be carried out in the shortest possible time ICC and without a great amount of etlort, yet any such arrangement must not detract from the strength characteristics ot the caps normally used for the purposes in question. Additionally, while the handling of the caps and props of such an arrangement must be simple, an absoluteiy safe guidance of the prop must be assured during the removal of the cap to prevent mishap to the workmen from a falling cap or prop or from an unintentional cave in of the roof.

It is an object of the present invention to overcome the foregoing drawbacks and to provide a roof support cap for mining prop means which contains bearing means for the head of a mining prop, yet which permits the cap to be removed from the prop even in low or thin horizontal seam areas of a mineway where there is no clearance left between the mine roof, cap and prop head to permit the lifting olf of the cap from the prop head in the usual Way.

it is another object of the present invention to provide a roof support cap of the foregoing type with a bearing recess means or socket for receiving the prop head therein, yet which permits the socket to be disassembled partially, whereby to provide a slideway longitudinally along the under side of the cap so that the cap may be displaced longitudinally on the prop head until the adjacent end of the cap is separated from the prop head.

It is still another object of the present invention to provide a roof support cap of the foregoing type which will permit the removal thereof from the prop head where it is undesirable or impossible to retract the prop means from the mine roof, and thus to permit the removal of the cap substantially without vertical displacement between the cap and the prop head in a direction away from one another.

It is still another object of the present invention to provide a roof support cap of the foregoing type which may be removed from a prop means in the shortest possible time and without a great amount of effort, even where the cap is jammed between the mine roof and prop head and the prop head is unable to be retracted further from the mine roof and cap.

It is still another object of the present invention to provide a roof support cap of the foregoing type which permits the cap to be removed from the prop by way of a construction which does not detract from the strength characteristics normally required in caps typically used in contemporary mining prop means.

It is still a further object of the present invention to provide a roof support cap of the foregoing type utilizing a construction permitting simple handling of the cap during its removal from the prop head as well as absolutely safe guidance of the prop during such cap removal.

It is still another object of the present invention to provide a roof support cap having a pair of bearing parts displaceable with respect to each other from a position in abutment with each other, whereby to form a bearing recess for a prop head of a mining prop, to a position removed from the abutment position, whereby to permit clearance between the bearing parts, and in turn, disengagement of the cap from which prop head at such bearing recess to allow simple and safe removal of the cap.

Other and further objects of the present invention will become apparent from a study of the within specication and accompanying drawings in which:

FIG. l is a side elevation of an articulated or hinged cap in accordance with one embodiment of the invention,

FIG. 2 is a plan View -of the cap of FlG. 1 showing schematically certain constructional developments along the under side of the cap,

FIG. 3 is a longitudinal schematic partial sectional view 3 taken along the line 3-3 of FIG. 2 and slightly enlarged to illustrate certain details of construction, and

FIG. 4 is a horizontal sectional partial view taken along the line 4 4 of FIG. 3 showing the divided bearing parts looking upwardly toward the under side of the cap.

It has been found in accordance with the present invention that a roof support cap having a pair of bearing parts displaceable with respect to each other from a position in abutment with each other, whereby to form a bearing recess for a prop head of a mining prop, to a position removed from the abutment position, whereby to permit clearance between said bearing parts, and in turn disengagement of the cap from a prop head at such bearing recess may be provided so that the removal of the cap will be facilitated, especially in those cases where it is impossible or impractical to retract further the prop head with respect to the cap and/or mine roof thereabove. The line of separation between the bearing parts is advantageously substantially cross-wise to the longitudinal direction of the cap, and one of the parts is displaceable longitudinally of the other part, while such other part is fixed from displacement.

Significantly, the cap is provided with a pair of spaced apart longitudinal ribs extending along the under side thereof, and the bearing parts are situated at correspondingly adjacent end portions of the ribs, such Ithat a removable pin may be inserted substantially cross-wise into both rib end portions at a longitudinal point along the cap. In this way, the one displaceable part may be situated longitudinally substantially between the other fixed part and the pin, and by providing an abutment surface on the displaceable part remote longitudinally from the fixed part and adjacent the pin, the abutment surface may be maintained in arresting engagement with the pin and the displaceable part in turn secured against displacement from the abutment position with respect to the fixed part, whereby only displacement longitudinally away from the fixed part of the displaceable part may occur upon removal of the pin from the rib end portions.

Specifically, the abutment surface is in the form of a cross-wise groove conforming to a portion of the circumference of the pin whereby the pin secures the displaceable part from longitudinal displacement and from transverse displacement as well. Advantageously, the ribs are provided with reinforcement members respectively at the rib end portions and corresponding coaxial bearing openings are defined in the rib end portions and the reinforcement members to receive the pin ends thereat.

Thus, in accordance with the present invention, a slide- Way is defined in the underside of the cap when the displaceable part and pin are removed, the slideway extending longitudinally from the space normally occupied by the displaceable part when in the abutment position and by the pin when inserted into the rib end portions, and along the space between the ribs to the corresponding end of the cap.

Referring to the drawings, FIG. 1 shows a cap 1 articulated at hinge 2 with a second cap 3 and having a bearing means 4 to accommodate thereunder the head of a mining prop. A similar bearing recess (not shown) may be provided in the second cap 3 so as to form a prop frame with a longitudinally extending skid more or less parallel to the caps 1 and 3. While FIG. 1 shows the vertical thickness of the cap 1, whereby to provide sufficient structural strength t-o withstand the load of a mine roof thereon, it may be seen from FIG. 2 that the roof cap 1 is laterally extending suiciently to provide a wide and long bearing surface for an appropriate roof area.

More particularly, as may be seen in FIGS. 3 and 4, the cap 1 is provided with a plate member 5 whose upper side is adapted to be placed into supporting engagement with the mine roof, and an under side which is adapted to contain the bearing means 4 of the invention. The bearing means includes a first bearing part 6 which is longitudinally displaceable and a second bearing part 7 which is fixed in place at the under side of plate member 5. Bearing part 6 is normally positioned in abutment with bearing part 7 along a substantially cross-line of separation 8, such that displaceable part 6 and fixed part 7, together form a common recess or socket 9 for the hemispherical head 1t) at the upper end of prop 11. While only the upper end portion of prop 11 is shown in FIG. 3, it will be realized that such prop represents a typical mining prop having telescoping members, for example, which may extend and retract with respect to one another in the manner of a piston cylinder arrangement. Longitudinally extending spaced apart ribs 12 depend from the under side of plate member 5 so as to provide structural stability to the cap 1 in the usual way. In order to maintain displaceable part 6 in the position of abutment at line of separation 8 with the appropriate portion of fixed part 7, a releasable retaining means, i.e., locking means, such as a removable pin 13 is maintained at a longitudinal point remote from fixed part 7 which corresponds with the remote portion of part 6 with respect to recess 9, which remote portion is provided with a transversely and downwardly extending abutment surface 15. Significantly, a curved groove 14 is defined transversely along abutment surface 1S so as to provide a seating barrier for pin 13 thereat, pin 13 arrestingly engaging surface 15 at groove 14 and in turn preventing longitudinal displacement of part 6 with respect to part 7.

Considering FIG. 4, more specifically, it will be seen that fixed part 7 is provided wit-h spaced apart lateral side portions 17 while displaceable part 6 is pr-ovided correspondingly with lateral side portions 18 conforming to the lateral side portions 17 of fixed part 7. The lateral side portions 17, together with the remainder of fixed part 7 along the line of separation 8 define a sl-ot 19 `facing part 6 and pin 13. The longitudinally extending spaced apart ribs 12 are interrupted along their length by the presence of the bearing means 4 of the invention, but due to the solid construction of the parts 6 Vand 7 and the reinforcement ribs 20 and 21, which form appropriate coaxial heaving openings 22 for pin 13, .the overall strength of the cap 1 is not diminished.

It will be seen that in order to remove the cap 1 from the prop head 10, in the case where it is not possible nor practical merely to ll'if-t ofi" the cap 1 from head 10, pin 13 may be knocked or tapped out from its position in `friction-al engagement with the bearing openings 22 in the ribs 12 and reinforcement ribs 2() and 21, whereupon displaeeable part 6 may be moved away from fixed part 7 and allowed to fall away from the cap. This will cause the cap at the under side of pla-te 5 to engage the head 10 of prop 11. A slight clearance -is now provided between the mine roof and prop head 1t), assuming the mine roo-f is located along the upper sid-e of plate member 5 (see FIG. 3). Such clearance is more or less measured 'by the thickness of displaceable part 6 at the portion thereof defining the appropriate confining area of socket or recess 9. Once the displaceable part 6 and pin 13 are removed, a guideway 16 will be provided for the prop head 10 longitudinally along the under side of plate member 5 of cap 1 Ifrom the line of separation S at fixed part 7 to the end of the prop having the connection at hinge 2. The hinge connection may be readily disassembled by removing the appropriate hinge pin and the opposite end of cap 1 may be allowed to tip downwardly until the same reaches the mine floor, such Itipping being carried out as the cap 1 is drawn along slideway 16 over the prop head 10 in the direction of hinge 2. Accordingly, an easy and safe removal of the cap 1 from its position on prop 11 may be provided utilizing a pair of separate bearing parts of the instant type, the cap being conducted longitudinally away from the prop as the prop head engages the slideway 16 until the appropriate end of the cap 1 passes outwardly beyond such prop head. Generally, one workman may carry ou-t the removal of the roof caps 1 in the manner of the invention inasmuch as the clearance afforded by the removable of the displaceable part 6 permits the cap to slide along the head 10 of the prop without upsetting the position of the prop 11 and without any danger of the cap l falling on the workman. Once the cap has been displaced to the end thereof adiacent the hinge 2, the cap will assume an angular position, with the end formerly connected with cap 3 being situated against head 10 and with the lthe opposite end resting on the ground.

It will be appreciated ,by the artisan, therefore, that the instant construction solves the problem of removing roof caps where there is little or no clearance between the prop head and the roof cap due to low mine roofs, ctc., the problem being solved by dividing the bearing means of the cap into a fixed and a displaceable or removable part in such a manner that the line of separation between the parts of the bearing means runs generally cross-wise of the cap. The pin takes -up the forces acting upon the displaceable or releaseable part by reason of the engagement of the prop head with the bearing means and at the same time the pin secures the displaceable or releasable part in its normal working position, i.e. the position at which the releasable part defines the bearing recess or socket with the fixed part. By yproviding such pin in arresting engagement with the releasable part of the bearing means and maintaining the long axis of the pin cross-Wise of the cap, the bending forces that are produced by the engagement of the prop head with the displaceable or releasable part are readily transmitted to the longitudinal reinforcing ribs of 'the cap. Such reinforcing ribs normally strengthen the cap against deformation and by providing additional rib means to achieve adequate width to keep the pin in place, i.e. in bearing openings in the ribs, all contemplated forces will be adequately ltaken care of despite the interruption of the longitudinal ribs by the presence of the bearing recess of the invention.

lt will be realized that while the releasable or displaceable bearing part may be removed simply by knocking out the pin, whereupon lthe prop head will slip autotmatically into the slideway between the longitudinal reinforcing ribs of the cap, any other locking means may be used which will accomplish the same purpose. In any case, when the releasable or displaceable bearing part is removed, the cap will still be carried on the prop head until the free end of the cap contacts the floor. As aforesaid, actually the cap will be pulled lengthwise over the prop head and this is possible `for the workman or miner to do more easily than heretofore, and in fact the comparatively heavy caps may lbe handled adeptly and with little chance of accidents that might occur if lthe caps should become immediately released from the prop head and should then have to be laid down.

Advantageously, in accordance with the present invention, even where comparatively uneven mine roofs are encountered, once the releasable or displaceable bearing part is removed, the prop head will slip into the slideway that is thus laid open, whereupon the cap will drop away from engagement with the mine roof suflioiently to permit the lengthwise sliding of the cap along the slideway over the prop head. Naturally, the hinge or link between the articulated caps 1 and 3 is first removed before the cap can be pulled over the prop head and guided outwardly and away from such prop head.

In accordance with a particular embodiment of the present invention, therefore, a roof support cap may be provided which comprises a longitudinal plate member having an upper side for engaging a mine roof and lan under side having socket bearing means for Imounting on the upper end portion of a mining prop, said bearing means including a pair of bearing parts situated longitudinally in tandem on the under side of the plate member,

one of the bearing parts being displaceable longitudinally with respect to the other bearing part, said other bearing part being fixed from displacement, the bearing parts being normally in abutment with each other to form t0- gether a socket bearing recess opening downwardly in a direction remote rfrom the upper side yof the plate member `for receiving the upper end portion of such mine prop therein, a pair of spaced apart longitudinal ribs extending downwardly from the under side of the plate member laterally outwardly of the one displaceable part and extending along the plate member from the displaceable part to the end thereof remote from the other fixed part, coaxial bearing openings being defined substantially transversely through the longitudinal ribs adjacent the displaceable part, a removable pin inserted substantially transversely into the ribs through the bearing openings and retained at the pin ends in the ribs by the bearing openings thereat, the displaceable part having at the end portion thereof remote from the fixed part a substantially transversely directed and downwardly extending abutment surface, said abutment surface having a curved groove defined therein conforming to a portion of the periphery of the pin and arrestingly engaged by the pin intermediate the pin ends when the dis-placeable part is in abutment with the fixed part, the fixed part having spaced apart lateral side portions extending from the socket bearing recess longitudinally toward the pin which, together with the remainder of the fixed part at the recess defined therebetween a slot, the displaceable part having lateral side portions conforming correspondingly to the lateral side portions of the fixed part and an abutment end conforming to the remainder of the fixed part, the displaceable part being received in the slot when in abutment with the fixed part, and when the pin is removed/from the ribs, and the displaceable part is displaced with respect to the fixed part and removed from the cap, the space occupied by the displaceable part and the space defined by the slot together with the space between the ribs and extending longitudinally at the under side of the plate member from the slot to the cap end remote from the fixed part provides a longitudinal slideway for the upper end portion of such mining prop along the under side of the cap to permit the cap to be removed from the prop without displacing the cap upwardly of the upper end portion of the mining prop.

It will be realized that the foregoing specification and drawings are set forth for the purposes of illustration and not limitation, and that various changes and modifications may be made herein without departing from the spirit and scope of the present invention which is to be limited only by the scope of the appended claims.

What is claimed is:

1. Roof support cap having situated on the underside thereof a pair of bearing parts together forming a downwardly directed common bearing recess for a prop head of a mining prop, and releasable retaining means for said bearing parts, said bearing parts being displaceable with respect to each other from a position retained by said retaining means in abutment with each other, whereby to form said `bearing recess for such a prop head of a mining prop, to a non-interfering position removed from the abutment position upon release of said retaining means, `whereby to permit clearance between said bearing parts and in turn disengagement of the cap from a prop head at such :bearing recess 'for removal of the cap.

2. Cap according to claim 1 wherein the line of abutment between said bearing parts defines a line of separation therebetween which is substantially cross-wise to the longitudinal direction of the cap and one of said parts is displaceable longitudinally of the other part, while such other part is fixed from displacement.

3. Cap according to claim 2 wherein said cap is provided with a pair of spaced apart longitudinal ribs extending along the underside thereof, and said bearing parts are situated at correspondingly adjacent end portions of said ribs, said retaining means including a removable pin inserted substantially crosswise into both the rib end portions at a longitudinal point along said cap, said one displaceable part being situated longitudinally substantially between said other tixed part and said pin, and said displaceable part having ian abut-ment surface remote longitudinally from said fixed part and adjacent said pin such that said abutment surface is in arresting engagement with said pin and said displaceable part secured against displacement from the abutment portion with respect to said fixed part and only displaceable longitudinally away from said fixed part upon removal of said pin from said rib end portions.

4. `Cap according to claim 3 wherein said abutment surface is in the form of a crosswise groove conforming to a portion of the circumference of said pin whereby said pin secures said displaceable part from longitudinal displacement and from transverse displacement.

5. Cap according to claim 4 wherein said ribs are provided with reinforcement lmembers respectively at said rib end portions and corresponding coaxial bearing o-penings are -delined in said rib end portions and said reinforcement members to receive the pin ends thereat.

6. Cap according to claim 5 wherein a slideway is vdefined in the underside of the cap when said displaceable part and pin are removed, said slideway extending longitudinally from the space normally occupied by said displaceable part when in the abutment position and by said pin when inserted into the rib end portions and along the space between said ribs to the corresponding end of the cap.

7. Roof support cap comprising a longitudinal plate member, having an upper side for engaging a mine roof and an underside having socket bearing means for mounting on the upper end portion of a mining prop, said bearing means including a pair of bearing parts situated longitudinally in tandem on the underside of said plate member, one of said bearing parts being displacea-ble longitudinally with respect to the other of said bearing parts, said other bearing part 'being fixed from displacement, said bearing parts being normally in abutment with each other to form together a socket bearing recess opening downwardly in a direction remote from the upper side of said plate member for receiving the upper end portion of such mining prop therein, a pair of spaced apart longitudinal ribs extending downwardly from the underside of said plate member laterally outwardly of said one displaceable part and extending along said plate member from said displaceable part to the end thereof remote from said other xed part, coaxial bearing openings being defined substantially transversely through said ribs longitudinally adjacent said -displaceable part, a removable pin inserted substantially transversely into said ribs through said bearing openings and retained at the pin ends in said ribs by said bearing openings thereat, said displaceable part having at the end portion thereof remote from said iixed part a substantially transversely directed and downwardly extending abutment surface, said abutment surface having a curved groove defined therein conforming to a portion of the periphery of said pin and arrestingly engaged :by said pin intermediate the pin ends when said displaceable part is in abutment with said lixed part, said fixed part having spaced apart lateral side portions extending from said socket bearing recess longitudinally toward said pin which together with the remainder of said iixed part at said recess define therebetween a slot, said displaceable part having lateral side portions conforming correspondingly to the lateral side portions of said fixed part and an abutment end con-forming to the remainder of said iixed part, said displaceable part being received in said slot when in abutment with said iixed part, and when said pin is removed from said ribs and said displaceable part is displaced with respect to said iixed part and removed from said cap, the space occupied by said displaceable part and the space defined by said slot together with the space between said ribs and extending `longitudinally at the underside of said plate member from said slot to the cap end remote from said fixed part provides a longitudinal slideway for the upper end portion of such mining prop along said underside to permit said cap to be removed from such prop without displacing said cap upwardly of the upper end portion of such mining prop.

8. In a roof support cap for mining prop means, in

which such cap has bearing means for a prop head of such prop means, the improvement which comprises such bearing means including a first bearing part and a second bearing part together `forming a downwardly directed common bearing recess o-n the underside of said cap for receiving such prop head, and releasable retaining means, said first bearing part being displaceable from a position retained by said retaining means in abutment with said second bearing part whereby to provide such bearing recess to a non-interfering position removed from the abutment position upon release of said retaining means whereby to permit cle-arance between said bearing parts and in turn disengagemment between such prop head and the cap at such bearing recess for removal of the cap from the prop means.

f 9. Improvement according to claim S wherein said releasable retaining means are in the form of locking means for locking said iirst part in the abutment position with said second part, the line of separation between said first and seco-nd parts being crosswise substantially of the longitudinal direction of the cap, said first part being positioned on said cap such that upon release of said locking means said first part is free to move out from the underside of the cap to per-mit such prop head and cap to become disengaged thereat and removed `from one another longitudinally substantially without vertical displacement therebetween.

References Cited by the Examiner FOREIGN PATENTS 1,002,264 10/1951 France.

921,707 3/ 1963 Gre-at Britain.

OTHER REFERENCES Gerlach: Germany application No. 1,027,157, Pub. 4/ 1958.

CLAUDE A. LE ROY, Primary Examiner. 

1. ROOF SUPPORT CAP HAVING SITUATED ON THE UNDERSIDE THEREOF A PAIR OF BEARING PARTS TOGETHER FORMING A DOWNWARDLY DIRECTED COMMON BEARING RECESS FOR A PROP HEAD OF A MINING PROP, AND RELEASABLE RETAINING MEANS FOR SAID BEARING PART, SAID BEARING PARTS BEING DISPLACEABLE WITH RESPECT TO EACH OTHER FROM A POSITION RETAINED BY SAID RETAINING MEANS IN ABUTMENT WITH EACH OTHER, WHEREBY TO FORM SAID BERARING RECESS FOR SUCH A PROP HEAD OF A MINING PROP, TO A NON-INTERFERING POSITION REMOVED FROM THE ABUTMENT POSITION UPON RELEASE OF SAID RETAINING MEANS, WHEREBY TO PERMIT CLEARANCE BETWEEN SAID BEARING PARTS AND IN TURN DISENGAGEMENT OF THE CAP FROM A PROP HEAD AT SUCH BEARING RECESS FOR REMOVAL OF THE CAP. 